This invention relates to improvements in the electrowinning of gallium and, more particularly, to an improved process for producing gallium by electro-deposition from an acidic gallium chloride solution.
According to U.S. Pat. No. 3,423,301 which issued on Jan. 21, 1969, high purity gallium can be deposited electrolytically from a purified gallium trichloride solution in an acid medium by controlling and maintaining the mole ratio of the concentrations of the trivalent gallium cations and the acid anions close to its stoichiometric value during the electrolysis. This process, however, requires a purified gallium trichloride solution. Moreover, the electrolysis is conducted at high current densities of from 3,000 to 10,000 amperes per square metre (A/m.sup.2) and a high current efficiency can only be maintained for short periods.